We are preparing Cr ions complexes of yeast enolase and its substrates and characterizing those complexes by physical means and with respect to catalytic parameters. We are preparing Cr ions complexes by exposing the above Cr ions complexes to air. The resulting exchange-inert complexes, we hope, will provide sufficiently stable bonds to allow us to isolate peptide(s) from the enzyme containing the metal ion attached to its native amino acid ligands. We are studying the role and catalytic parameters of the enzyme we have recently discovered, phosphoglycolate phosphatase from human erythrocytes. The existence of this enzyme which has never before been found outside of plant cells, implies the presence of phosphoglycolate in erythrocytes. This compound has powerful effects on the enzymic system that determines 2-3 diphosphoglycerate levels which in turn controls oxygenation. We are hunting for this metabolite in these cells. BIBLIOGRAPHIC REFERENCES: J. A. Badwey and E. W. Westhead, "Post-Translational Modification of Human Erythrocyte Pyruvate Kinase." Bioch. Bioph. Res. Comm. 74, 1326 (1977). D. J. Green, D. B. Sattelle, E. W. Westhead and K. H. Langley, "Relative Size and Dispersity of Isolated Chromaffin Granules." Chapter in Photon Correlation and Light Beating Spectroscopy, eds. E. R. Pike and H. Z. Cummins, Plenum Press 1977, in press.